On the Prevalence of Schizophrenia and Transforming Care Through Research

March 14, 2018
Joshua A. Gordon, MD, PhD
Volume 35, Issue 3

A response from the NIMH director.

Editor's note: This commentary is part of a 3-part collection:

Mental illnesses affect tens of millions of people in the US each year. As the lead federal agency for research on mental illnesses, the mission of the National Institute of Mental Health (NIMH) is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery, and cure. NIMH, part of the National Institutes of Health (NIH), strives to provide the public with up-to-date, accurate information on our understanding of mental illnesses and the tremendous burden these illnesses pose to individuals and their families. To this end, we include prevalence statistics on our public-facing website to provide a framework for understanding the scope and impact of mental illnesses.

NIMH recently undertook an effort to refresh the statistics pages on our website, with respect to both design and content. For all statistics we report, our goal is to use the most accurate data available, which includes consideration of the most recent findings, as well as quality of the data. To help users understand and interpret the statistics we present, we aim to be rigorous and transparent by providing adequate background and context, as well as information on relevant strengths and limitations of the data sources. In the case of the refreshed schizophrenia statistics page, we used findings from several papers to approximate an estimate for the prevalence of schizophrenia. We now recognize, in retrospect, that we did not provide sufficient context to understand or justify the selected prevalence estimate, nor did the number we settled on reflect the full spectrum of knowledge available in the relevant literature.

Accurate and stable estimates of the prevalence of schizophrenia are made challenging by many factors. Comparisons across studies are hindered by inclusion of varying combinations of diagnostic criteria (eg, schizophrenia/schizophreniform; schizophrenia and other psychotic disorders; non-affective psychotic symptoms). The very definition of schizophrenia itself has changed over time since the DSM-III-based Epidemiologic Catchment Area (ECA) paper reported the prevalence of 1.1% in 1981.1 More recent surveys might under-count those with serious mental illness for many reasons, including the fact that many of these individuals decline to participate in surveys, or are homeless or incarcerated or otherwise difficult to reach. However, in the years since the ECA, a large number of studies, including several in the US, have clearly demonstrated that the 1.1% figure is no longer scientifically defensible.

But that does not mean the new figure we initially arrived upon – 0.3% – necessarily reflects the full picture. We are in the process of expeditiously reviewing and updating the information presented on our webpage to more fully reflect the available data on schizophrenia prevalence. We anticipate providing an estimated range, rather than a single point estimate; reporting such results will require inclusion of relevant caveats and limitations. More broadly, timely and accurate information on the prevalence of schizophrenia and other mental illnesses is important to multiple Department of Health and Human Services agencies beyond NIMH, including the Substance Abuse and Mental Health Services Administration (SAMHSA) and the Centers for Disease Control and Prevention. By working together toward a solution to address the difficulties in estimating prevalence for schizophrenia and other serious mental illnesses, we can accomplish far more for our key stakeholders. NIMH looks forward to continuing to work collaboratively to advance these important objectives. I thank Dr. Torrey and Ms. Sinclair for bringing the need for this more thorough treatment of schizophrenia prevalence to our attention.

At the same time, I feel compelled to counter the notion that NIMH does not devote sufficient attention to serious mental illness. NIMH supports a diverse portfolio of research aimed at improving care for, and the lives of, individuals living with a serious mental illness. This research spans basic and translational sciences aimed at identifying and developing the breakthrough treatments of tomorrow, as well as services and intervention sciences aimed at optimizing and implementing the effective treatments of today.

For example, neurocognitive dysfunction is a hallmark of schizophrenia and represents an important, and untreated, component of the disability associated with the disorder. NIMH supports several cognitive remediation studies for individuals with psychosis aimed at improving cognition and functional outcomes. We are also supporting the development and testing of 3 novel compounds for their long-term potential to improve cognition in patients with schizophrenia.

NIMH funds several large-scale effectiveness trials of practical interventions to reduce premature mortality in people with serious mental illness by addressing health risk factors. Recognizing that modifiable health risks associated with premature mortality appear early, NIMH also funds research capitalizing on opportunities for early intervention with young people at high risk. Additional efforts test interventions aimed at improving overall functioning by focusing on employment, social engagement, and community integration. These are but a sampling of the many research projects of relevance to serious mental illness supported by NIMH.

Notably, NIMH-supported research is impacting people now. For example, the NIMH-funded Recovery After an Initial Schizophrenia Episode (RAISE) project, a large-scale comparative effectiveness research study, demonstrated that coordinated specialty care early in the course of treatment for first episode psychosis was superior to usual care in reducing symptoms, improving school and work functioning, and increasing quality of life. Importantly, the intervention tested in RAISE was found to be cost-effective. Based on results from RAISE, the Centers for Medicaid & Medicare Services extended Medicaid coverage for coordinated specialty care and SAMHSA set aside 10% of its Mental Health Block Grant allocation for each state to support evidence-based programs that target first episode psychosis. Today over 200 coordinated specialty care programs operate in 49 states, representing an unprecedented translation of scientific findings into services that directly benefit persons with early serious mental illness.

Most importantly, we must keep in mind that statistics, while useful, do not tell the full story of the tremendous burden shouldered by individuals and families living with schizophrenia, and the outsized impact this burden has on our society. NIMH will continue to aggressively support novel approaches to biological understanding, therapeutics development, and services and intervention delivery, all aimed at reducing this burden.

References:

1. Regier DA, Narrow WE, Rae DS, et al. The de facto US mental and addictive disorders service system. Epidemiologic catchment area prospective 1-year prevalence rates of disorders and services. Arch Gen Psychiatry. 1993;50:85-94.